Rheem is one of the most profound brands in the water heater Industry. The tankless water heater models from Rheem are a common choice amongst most households across India. Every device from Rheem tankless water heater comes with an amazing heating technology equipped to deal with peak hour requirements.

There are many parts of this water heater, and you may face a slight technical problem while running it at times. The good part is that Rheem tankless water heaters come with an LED display on the front that shows up an error code whenever there is a problem. also with this glance performance sometimes you will face trouble on Rheem tankless water heater error code 13.

Once you get this specific error Code 13, this quick guide below will help you get over it. How serious is this error? Let’s find out!

Rheem Tankless Water Heater Error Code 13

Why does Error Code 13 happen?

The Error Code 13 is not very common when it comes to using a Rheem tankless water heater. However, if you face this problem, it is detecting a malfunction in your heater’s combustion system. Precisely, it indicates the Oxygen depletion sensor or even the flame rod FL 24 of your heater. There could be a few reasons why you are facing this issue. But if you face it, you need to check multiple components of the Rheem tankless water heater.

Last update on 2022-01-25 / Affiliate links / Images from Amazon Product Advertising API

Finding out the source Rheem Tankless Water Heater Error Code 13

Before you start working with the device, the first thing you need to do is diagnose the source of the problem. You can follow the steps mentioned below to diagnose the exact source of the Error 13 code.

  • The first step is to look for the air intake system of your heater. It may often happen if the venting system of your heater is not properly done. You need to open up the panel and check this space.
  • The next thing that you need to do is to have a close look inside the venting duct. Often small dust articles or clogged venting systems may lead to this problem. Getting rid of this issue should be a priority.
  • If you did not find any problem, go over to the altitude settings of the device, and you will be able to see that the device has proper settings installed or not. You can configure this.
  • The next step would be to go to the flame rod of your heater. You need to bring the heater down and then check the flame rod. It should be mentioned as FL-24 on your heater.
  • Another thing that you need to do is to check the blower motor of your heater. If the heater motor is not functioning properly, it should display the error 13 code.

What to do if you have Error Code 13?

If you face Error Code 13, you can quickly follow up the few steps mentioned below to get over with this. Once the diagnosis is made, here are a few possible solutions mentioned below to help you get the best results.

  1. Create a simple restart

Sometimes, it may be just because of a small technical fault from your heater. The first things you need to do are power on the unit and flush off the water inside. Now hold the rest button of your heater and allow the Rheem water heater to undergo a reset.

  1. ODS Failure

The oxygen depletion system is another major component of the heater. If the ODS is not working properly, your water heater may tend to shut down. In such a case, you need to go to the maintenance mode of your heater. There should be a cell ØA, which will mean that you can get a complete setup involved. In such a case, alter the settings and get the device to a maintenance mode. If it is not working, you will have to think about replacing the sensor.

How does Rheem Tankless Water Heater work?

As we all know, there is no storage system included in a tankless hot water unit. It all depends on a heating element that allows the heater to heat the entire system. A cold water inlet pipe and a valve allow a continuous water flow when the heater is in use. When the cold water flows through the line, the heating element starts to heat the water. With the hot water faucet, you will be able to receive warm water instantly. The flow of water involves many procedures, which include heat exchangers. It also comes with multiple sensors that can track the data and all you t receive hot water.

Why is the ODS important in a Tankless system?

There is a sensor on tankless water heaters that distinguishes when you turn on a hot water faucet. As this happens, the tankless unit will activate, leading to a progression of heating components that heat the water and keep on doing so until the stream sensor perceives the water has been killed. Fundamentally, as soon as you turn off the faucet, the heating cycle stops.

A tankless heater will just run a couple of moments per day rather than turning on and off for the duration of the day like a tank-type water heater that has to heat a large tank brimming with unused water always. Thus, this can save you a tremendous amount of energy costs.

Are Rheem water heaters any Good?

A tankless operates with a heat exchanging system that is just activated by the approaching stream. So energy is possibly being utilized when you are using water. Because there is no limit to hot water, you could now wash the dishes, do the laundry and take a pleasant hot shower at the same time. With a standard heater, you are helpless to floods and mineral stores if it has become too old. If a “tank” breaks, then there is the chance of a leak or flood creating. Tankless systems are also considerably more compact and can find a way into places that regular water heaters proved unable to.

When do you need to replace a Rheem Tankless Water Heater?

To know how to replace water heating gadgets will be helpful just if you know when you ought to replace the water heater. This is a confounding point and can dumbfound even the most clear-headed individual.

It would help if you thought about its age. While gas heaters work anywhere between 8-12 years, electric ones between 10-15 years, and tankless heaters have a more drawn out life expectancy.

When this period is covered, you know the time has come to replace the heater. Similarly, if you start getting rust-hued hot water or cold water, then its replacement of the heater is late.

Before you start replacing a water heater, you need to guarantee that you have all the necessary devices like a hacksaw, screwdrivers, and other essential apparatuses. The next thing you need to do is turn off the electricity or gas supply and water supply to the water heating gadget. It is then an ideal opportunity to drain the heater by allowing the air to out of the heater. Eliminate the wiring gradually. If the pipes to the water supply cannot be eliminated manually, you need to cut them with a hacksaw’s assistance. Nonetheless, it would help if you replaced them with new pipes once you cut them out of the heater.

Last update on 2022-01-25 / Affiliate links / Images from Amazon Product Advertising API


Rheem Tankless Water Heater Error Code 13 is not a standard error to turn up when it comes to using a Rheem tankless water heater. However, if you face this issue, the one thing that you need to do is to work this out immediately. If you cannot do this all by yourself, contacting a professional will be the most sensible thing to consider. It is also important to be steady while working with your tankless water heater system. Make sure that you take all the safety precautions before working.

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